Apparatus for crimping textile strands



Sept. 14, 1965 K. lWNlCKl ETAL APPARATUS FOR GRIMPING TEXTILE STRANDS 2Sheets-Sheet 1 Filed July 15, 1963 In en 0! tJ 9 Attorneys Sept. 14,1965 K. IWNICK] ETAL 3,205,554

APPARATUS FOR CRIMPING TEXTILE STRANDS Filed July 15, 1963 2Sheets-Sheet 2 F/GZ.

Attorneys 3,205,554 APPARATUS FOR CRIMPENG TEXTILE STRANDS Kurt Iwnicki,Ponthir, and David B. Miller, Stanmore, England, assignors to BritishNylon Spinners Limited, Pontypool, England Filed July 15, 1963, Ser. No.294,991 Claims priority, application Great Britain, July 19, 1962,27,714/62 6 Claims. (Cl. 28-1) The invention concerns improvements in orrelating to apparatus for crimping textile strands, and it hasparticular reference to such apparatus comprising a stufferbox.

In the specification of an application filed on even date hereto, wehave described a process for crimping textile strands, such as yarns ofnylon, in which process the strands are crimped and the crimp is set,which is characterised in that the back pressure exerted on a strand atthe point of crimping is maintained constant by a continuous control ofsuch pressure effective at a location intermediate of said point ofcrimping and the point of initiation of pressure on the strand withinthe stulfer-box, and in that the crimp is set whilst the strand is underpressure within the stutter-box.

Such a process affords considerable advantages over knownprocesses forstuffer-box crimping in that a better control of both crimpinguniformity and setting uniformity is allowed.

An object of this invention is the provision of apparatus that issuitable for use in the aforementioned process; and a further object isthe provision of apparatus which is an advance over known stutter-boxcrimping apparatus in respect of the responsiveness of itspressure-controlling system and in respect of the clean lines of theinterior of the stutter-box which obviates snagging of the strands, orof filaments composing the strands, and any tendency for the crimp to beremoved on withdrawal of the strand.

According to the invention, a stufler-box crimper has a dividedcompression chamber whose input and output end-portions are mounted soas to allow limited lengthwise movement relative to each other to occur.

Thus, the crimper may comprise nip-rolls, by which the strand is forcedinto the compression chamber, a compression chamber preferably but notnecessarily of rectangular cross-section, which chamber is divided intoa crimping zone end-portion and a setting zone end-portion, the latterbeing mounted for limited lengthwise movement relative to the former andhaving a strand discharging end which is restricted sufficiently toinitiate a back pressure in the column of strand material within thechamber.

Although the expression setting zone end-portion is used above, it is tobe understood that this end-portion need not, in fact, be employed forsetting the strand material within it, if that is not desired. Theexpression is used for convenience of description only, as theend-portion will normally be so employed.

In a presently preferred embodiment, the nip-rolls are stainless steelrolls of /8 inch peripheral width, and the walls of the compressionchamber are of tool steel. The nip-rolls are spaced so that theirperipheries are a few thousandths of an inch apart. The internalcross-section of the compression chamber is substantially uniformlyrectangular throughout its length, although the area of thecross-section of the setting zone end-portion is slightly larger thanthat of the crimping zone end-portion.

The walls of the crimping zone end-portion comprise flat front and backwalls spaced, at the top of the zone, some few thousandths of an inchfrom the sides of the nip rolls, and side walls in the form of bladeswhose United States Patent 0 shaped tips are closely spaced from theperipheries of the nip rolls. The other ends of the blades are cut downto thin strips which can fit into the mouth of the setting zoneend-portion.

The setting zone end-portion, whose length is preferably greater thanthat of the crimping zone end-portion, is mounted on a simple parallelspring strip mounting so that it can adopt various closely-spacedpositions relative to the crimping zone end-portions, depending on theamount of strand material within the compression chamber. Further, it isloaded with a fixed load tending to urge it towards the crimpingchamber, which fixed load, comprising a counter-balance weight and aback-pressure weight when the direction of crimping is downward, isresponsible for the constant control of the crimping backpressure in thecrimping zone. Thus, small changes in the amount of strand materialwithin the compression chamber will not lead to changes inback-pressure, and hence in the nature of crimp imparted, because suchchanges will be accommodated by small movements, towards or away fromthe crimping zone end-portion, of the setting zone endportion withoutalteration of the pressure exerted thereby on the strand Within thecrimping zone.

Instead of being spring-mounted, however, the setting zone end-portioncan be mounted on guide-rods for pure vertical movement relative to thecrimping zone end-portion, and a load applied as described above.

The strand-discharging end of the setting zone end portion is restrictedby, for instance, a flap formed at the end of the front or back wall ofthe end-portion, which flap is directed inwardly towards the oppositewall and fixed in a given position. Alternatively, the front or backwall can be itself constructed so that its end is shaped so as to extendinwardly in this way. The advantage of a flap, however, is that theamount of its inward extension, i.e. the angle that it makes with thelength direction of the front or back wall, can be adjusted to give theoptimum results with various crimping processes. v

The walls, or some of them, of the setting zone endportion may beheated, e.g. by electrical resistance heaters, over all or part of theirlengths. The whole, or that portion of thet setting zone end-portionwhich is heated, may be enclosed within a heater jacket containingheatinsulating material. The temperature of the setting zone may bethermostatically controlled at the required temperature.

The invention will now be described by reference to the accompanyingdrawings in which FIGURE 1 is a front elevational view of one embodimentof the invention, shown partly in section where cut away; and

FIGURE 2 is a side view, partly in section, of the apparatus of FIGURE1.

The apparatus of this embodiment comprises nip rolls, 1, 2 each of whichis driven in the directions shown by the arrows in FIGURE 1. The driveis transmitted from endless bands 3, 4 (FIGURE 2) through pulley-wheels5, 6 and gearbox 7. As shown in FIGURE 1, yarns Y converge at guide 9before being led around a portion of the periphery of feed roll 11pivotally mounted on arm 13 and held in contact with the periphery ofnip roll 2 by means of weight 15 on the end of arm 13.

Nip rolls 1, 2 form the entry to the crimping zone endportion which isfurther bounded by front wall 17, back wall 19 and side walls 21, 22.Side walls 21, 22 have extensions 23, 24 at their lower ends which fitinto the mouth of the setting zone end-portion, to be described below.

The setting zone end-portion consists of a rectangular cross-sectionsetting chamber 25 the main length of which is enclosed within a heaterjacket 27. The end-portion is mounted on flexible steel springcantilever arms 28, 29; and it is loaded, to be urged upwardly towardscontact with the crimping zone end-portion, by means of weights 31 hungon the end of strand 33 passed around pulley wheel 35.

The discharge end of the chamber 25 is restricted by I means of hingedflap 37 adjustably fixed in a desired position by means of screw 39. Thefront and back walls of the chamber are heated by electrical resistanceheaters 41, 42, and the spaces 43, 44 within the jacket 27 may be filledwith heat-insulating material.

The crimped yarn Y, is positively withdrawn from the setting chamber 25around pin 45 by wind-up means (not shown).

What we claim is:

1. A stufier-box crimper consisting of a compression chamber into whichyarn is forced and in which it is held under pressure, said compressionchamber being divided into an input end-portion defining a crimping zoneand an output end-portion defining a setting zone, said outputend-portion having a restricted strand-discharging end, and said outputend-portion being mounted in a manner allowing for limited lengthwisemovement relative to said input end-portion.

2. A stutfer-box crirnper consisting of a compression chamber into whichyarn is forced and in which it is held under pressure, said compressionchamber being divided into an input end-portion defining a crimping zoneand an output end-portion defining a setting zone, said outputend-portion having a restricted strand-discharging end, and said outputend-portion being mounted on flex 'ible cantilever arms for limitedlengthwise movement relative to said input end-portion.

3. A stuifer-box crimper consisting of a compression chamberinto whichyarn is forced and in which it is held under pressure, said compressionchamber being divided into an input end-portion defining a crimping zoneand an output end-portion defining a setting zone, said outputend-portion having a restricted strand-discharging end, and said outputend-portion being mounted in a manner allowing for limited lengthwisemovement relative to said input end-portion and being loaded, to urge ittowards said input end-portion so as to provide crimping back-pressurethrough'said yarn in said chamber.

4. Crimping apparatus comprising: a stutter-box compression chamberhaving a crimping zone defined by a yarn input end-portion and a yarnoutput end-portion having a yarn discharge aperture, said outputend-portion being formed separately from said input end-portion andmounted for limited movement relative to said input end-portion in theplane of yarn movement; means for creating back pressure on yarn in saidchamber including means for positively feeding yarn into said inputendportion and means restricting said discharge aperture; and means formaintaining constant back pressure during small changes in the amount ofyarn withinsaid chamber, said means including a constant load urgingsaid output end-portion toward said input end-portion whereby smallchanges in the amount of yarn within said compression chamber result insmall movements of said output end-portion in the plane of yarnmovement.

5. Apparatus as in claim 4 in which said yarn discharge aperture is offixed dimensions.

6. Apparatus as in claim 4 wherein said yarn input endportion has a boredefined by front, back and side walls, said side walls having extensionsterminating beyond said front and back walls in the direction of yarnmovement and projecting into said output end-portion, said outputend-portion being slightly spaced from said input end-portion and havinga bore which receives said side wall extensions, the space between saidend-portions being traversed in the direction of yarn movement by saidside wall extensionsand being free of front and back walls.

References Cited by the Examiner UNITED STATES PATENTS 2,865,080 12/58Hentschel 2872 3,009,310 11/61 Murchie et al. 28---72 3,023,481- 3/62Scragg 19--66 3,046,633 7/62 Ohashi et al. 281

FOREIGN PATENTS 316,685 10/56 Switzerland.

DONALD W. PARKER, Primary Examiner.

1. A STUFFER-BOX CRIMPER CONSISTING OF A COMPRESSION CHAMBER INTO WHICHYARN IS FORCED AND IN WHICH IT IS HELD UNDER PRESSURE, SAID COMPRESSIONCHAMBER BEING DIVIDED INTO AN INPUT END-PORTION DEFININGA CRIMPING ZONEAND AN OUTPUT END-PORTION DEFINING A SETTING ZONE, SAID OUTPUTEND-PORTION HAVING A RESTRICTED STRAND-DISCHARGING END, AND SAID OUTPUTEND-PORTION BEING MOUNTED IN A MANNER ALLOWING FOR LIMITED LENGTHWISEMOVEMENT RELATIVE TO SAID INPUT END-PORTION.